Two long, parallel wires carry currents of I 1 = 2.82 A and I 2 = 4.70 A in the

Question

Two long, parallel wires carry currents of I1 = 2.82 A and I2 = 4.70 A in the direction indicated in the figure below. (Choose the line running from wire 1 to wire 2 as the positive x-axis and the line running upward from wire 1 as the positive y-axis.)

(a) Find the magnitude and direction of the magnetic field at a point midway between the wires (d = 20.0 cm).

(b) Find the magnitude and direction of the magnetic field at point P, located d = 20.0 cm above the wire carrying the 4.70-A current.

Explanation / Answer

a) SInce the currents i1 and i2 are in same directions then

the magnetic fields produced by theses currents are in opposite directions

B = B1-B2 = mu_0*i1/(2*pi*r) = ((2*10^-7*2.82)/0.1)-((2*10^-7*4.7)/0.1)

B = -3.76*10^-6 T

B = 3.76*10^-6 T = 3.76 uT

direction is 90 degrees below the positive X-axis

B) B1 = mu_o*i1/(2*pi*r) = (2*10^-7*2.82)/(1.414*0.2) = 2*10^-6 T

B2 = mu_0*i2/(2*pi*r) = (2*10^-7*4.7)/(0.2) = 4.7*10^-6 T

B = sqrt(B1^2+B2^2+(2*B1*B2*cos(45))) = sqrt(2^2+4.7^2+(2*2*4.7*cos(45))) = 6.27*10^-6 T = 6.27 uT

45 degrees to the left of the verticle

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.